1. Field of the Invention
The invention is related to a winch installation comprising a rotatably supported main winch device, such as a drum, for winding or unwinding an elongated flexible object such as a wire or cable. Such winch installation is widely known, and can be used for winding or unwinding all kinds of wires or cables, such as electric, hydraulic, pneumatic wires, steel cables, umbilicals of all kinds and so on. In so far as such objects are of a relatively flexible nature, the winding and unwinding process proceeds rather smoothly and usually does not give rise to particular problems.
2. Description of the Related Art
In specific applications, e.g. umbilicals which are provided with intermediate segments which are of a relatively rigid or stiff nature, the process of winding and unwinding can become more cumbersome. The relatively rigid segments are not flexible enough to follow the curved contour of the winch, which means that special precautions have to be taken when winding or unwinding such segmented umbilicals. Reference is made to U.S. Pat. No. 4,725,088, describing a lifting system according to which the relatively stiff segments are to be removed from the cable before winding said cable to the winch drum.
The disadvantage of such lifting system is obvious. Each time the stiff segments in question have to be dismounted from the cable upon winding said cable onto the winch drum, or have to be mounted onto the cable again upon unwinding thereof. Such process is cumbersome and time-consuming, and not fit for frequent winding and unwinding operations.